The meme doesn't stigmatize mental illness because it's not talking about mental illness.

If anything, pathologizing the predictable and inescapable results of living under oppressive systems designed to keep you as down and alienated as possible as a mental illness, instead of a perfectly valid reaction to living in dystopia deeply and negatively impacts how we treat actual mental illness.

The idea that pointing out that we have societal problems pills can't solve is somehow stigmatising actual mental illness (which pills can help) just goes to show how deeply indoctrinated society is in to toxic individualism.

I concur

This was also my takeaway. The comic isn't making a value determination for medication in any form, but instead commenting that we as a society would rather address symptoms rather than address any root causes.